"Filipinos offer food even to strangers"
Philippines Local Custom Tip by joiwatani

When a Filipino is eating and you happen to pass by while he is eating, he says "Let's Eat!" and offer you to eat some of his food. It is impolite for Filipinos to eat without offering their food. However, this does not mean that you will go and eat his food.

Just say "Thank you, I already ate!" (Although you have not eaten yet!).